Mathematics is merely the means to a general and ultimate knowledge of man.

We are so fond of being out among nature, because it has no opinions about us.

A casual stroll through the lunatic asylum shows that faith does not prove anything.

Good manners disappear in proportion as the influence of a Court and an exclusive aristocracy lessens; this decrease can be plainly observed from decade to decade by those who have an eye for public behavior, which grows visibly.

If we make sacrifices in doing good or in doing ill, it does not alter the ultimate value of our actions; even if we stake our life in the cause, as martyrs do for the sake of our church : it is a sacrifice to our longing for power, or for the purpose of conserving our sense of power.

Men subsequently put whatever is newly learned or experienced to use as a plowshare, perhaps even as a weapon: but women immediately include it among their ornaments.

Do you believe then that the sciences would ever have arisen and become great if there had not before hand been magicians, alchemists, astrologers and wizards, who thirsted and hungered after abscondite and forbidden powers?